Gas-burner.



PATENTED DEC. 6, 1904.

' D. B. FRASER.

GAS BURNER.

APPLIOATION FILED DEO.31, 1903.

N0 MODEL.

lNVENTOR UNITED STATES Patented December 6, 1904.

PATENT OFFICE.

GAS-BURNER.

SPECIFICATION forming part of Letters Patent No. 776,659, dated December6, 1904. Application filed December 31, 1903. Serial No. 187,256. .Nomodel.)

To aZZ whmn it may concern:

Be it known thatI, DAVID B. FRAsER, a subject of the King of GreatBritain, and a resident of New York, in the county of New York and Stateof New York, have invented certain new and useful Improvements inGas-Burn ers, of which the following is a specification.

The invention relates to improvements in gas-burners;. and it consistsin the novel features hereinafter described and claimed.

My invention pertains more particularly to burners for use in generatingheat to be used for roasting, cooking, and likepurposes, and in thisapplication I present my invention as embodied in a gas-burner adaptedfor use .in coffee-roasting apparatussuch, for illustration, as thatdescribed and claimed in Letters Patent No. 627,993, granted to me onJuly 4:, 1899.

The object of my invention is to produce a burner affording the maximumefficiency with the minimum consumption of gas, and to this end theburner of my invention embraces two features of novelty, one residing inthe form of the burner in cross-section and the other in the specialarrangement of the exit or ignition apertures therein for the gas.

In carrying out the first feature of my invention in its preferredembodiment 1 construct the burner in the form of an elongated shellhaving exit-apertures in one portion of its upper wall and containing aninterior chamber which is approximately of crescent shape incross-section or of concavo-convex outline with the concave form at thelower side of the shell, which at one end receives the gas and air andaffords a mixing-chamber and throughout a suitable portion of its lengthbeyond the mixing-chamber constitutes the burner proper.

In accordance with the second feature of my invention I arrange theexit-h0les or ignition-apertures in straight rows or lines extendingtransversely of the burner and at right angles to the line of the flowof gas through the burner, the holes in each row or line being as closetogether as it may be possible to have them and the rows or lines ofholes being uniformly spaced from one another in series, there being aspace of about two inches between each two rows of holes.

The invention will be more fully understood from the detaileddescription hereinafter presented, reference being had to theaccompanying drawings, in which- Figure 1 is a top view of a gas-burnerconstructed in accordance with my invention, the said burner being of aform applicable for use in the coffee-roaster of the aforesaid LettersPatent N 0. 627,993. Fig. 2 is an enlarged front end view of same. Fig.3 is a transverse section of same on the dotted line 3 3 of Fig. 4. Fig.4: is a longitudinal section, partly broken away, of same on the dottedline i 4 of Fig. 2. Figs. 5, 6, and 7 are diagrammatic end views ofseveral modified forms of the burner; and Fig. 8 is a side elevation ofthe front portion of the burner represented in Figs. 1 to 4-, inclusive.

Referring to Figs. 1, 2, 3, 4, and 8, the numeral 20 denotes the burneras a whole, and, as will be seen, this burner is in cross-section ofconcave-convex outline and comprises an outer section 21 and an innersection 22, both sections preferably being of arch form and securelybolted together at their lower side edges. In the preferred constructionthe outer section 21 will preferably define a half-circle and the innersection 22 a smaller are of the same size of circle, whereby there isformed between the said sections a crescent-shaped chamber 23 for theair and gas, said chamber 23 along its outer wall defining a half-circleand along its inner wall less than a half-circle and graduallydecreasing in depth toward its side edges, the depth of said chamberbeing considered as on radial lines extending from the center of thecircle of which the outer wall of said chamber defines half. The saiddecrease in the depth of the crescent-shaped chamber 23 is important inattaining the best results and the maximum gas-pressure within theburner, and the said chamber 23 is uniform in cross-sectional areathroughout its length, which is also a feature of importance in securingmaximum efliciency.

The front end of the burner 20 is provided with a gate 24, preferablyhinged, to control the admission of air to the chamber 23, and this gate24 is slotted to pass over the inlet gas-pipe 25, leading from anysuitable source of supply. The gate 24 carries at its opposite loweredges suitable screws and thumbnuts 26 for cooperation with slottedsegmental bars 27 fastened to the burner in securing the gate in any ofits adjusted positions in an obvious manner, it being desirable that thegate should be less open in starting the burner into operation thanthereafter.

The rear end of the burner 20 is closed by means of the verticalcresentshaped flange 28, formed on the section 21 and bolted at itslower edges to the end of the lower section 22. The upper section 21 isthroughout the first portion of its length left unperforated, wherebythe first portion of the chamber 23 is made to constitute amixing-chamber for the gas and air, while beyond this mixing-chamber thesaid section 21 is provided with the series of rows of radially-disposedholes or ignition-apertures 29, these rows of holes extending ontransverse lines across the section 21, from one side to the otherthereof, and being at right angles to the line of the fiow of gasthrough the chamber 23 or at right angles to the longitudinal line ofsaid chamber. The apertures or holes 29 in each row are as closetogether as it is practicable to make and have them, and the rows ofholes are separated from one another by uniform spaces of about twoinches each.

One of the important features of the elongated burner is that its uppersurface is projected upwardly and presents a greater surface area thanits lower surface, whereby there is formed an interior chamber which isshallow but of considerable extent laterally considered, and in thepreferred embodiment of the invention of gradually-decreasing depthtoward its side edges, the result of this construction being a verygreat increase in the efficiency of the burner and economy in the gasconsumption.

In Figs. 1 to 4, inclusive, I show the preferred form of the burner, andthis form has been hereinbefore sufficiently described. I do not wish,however, to confine my invention to the precise form of burner shown inFigs. 1 to 4, inclusive, since this form may be modified somewhatwithout departing from the broader scope of my invention-as, forillustration, the inner chamber 23 may be given a more extended and morepronounced crescent outline, as shown in Figs. 6 and 7 and the burnermay be made in one piece, as shown in Fig. 6, or it may be made from atube or pipe, with a filling 30 introduced therein to create the chamber23 of crescent outline. The form of burner shown in Fig. 5 is ofconcavo-convex outline in cross-section, and its upper surface presentsa more extended area than its lower surface. The

chamber of the burner shown in Fig. 5 is uniform in depth-that is,radially considered the said chamber does not decrease in depth towardits side edges, as does the chambers of the burners shown in Figs. 3, 6,and 7. The chamber of the burner shown in Fig. 5 defines more than ahalfcircle, and said chamber is of uniform cross-sectional area throughoutits length.

The burners hereinbefore referred to will of necessity vary in length inaccordance with the special conditions of their uses.

I prefer that one end of the burner structure be utilized as amixing-chamber for the gas and air; but with less satisfaction themixing of the gas and air may take place outside of the burner structureor in a chamber separate therefrom but leading thereto.

I do not of course limit the invention to the placing of the gate 24 andsupply-pipe 25 at the vertical end of the burner 20, since thesefeatures are common in the art and they may be arranged at a horizontalportion of the burner instead of more conveniently at the vertical endthereof without departing from my invention.

The arrangement of the ignition holes or apertures 29, hereinbeforedescribed, is of special value in a burner having the special chamber 23and is also of value in burners of other forms, such as a tubular burnerof the character disclosed in my aforesaid Letters Patent. The burnersreferred to afford an extended upper outer surface for the straight rowsof small round holes 29, the burner shown in Figs. 1 to 4, inclusive,being the preferred form of burner and presenting an effective surfacearea about equal to that of a half-circle for the said rows, whichshould be at least two inches apart from center line to center line, sothat the flames along the rows of holes may not commingle.

I do not confine the invention in respect of the form of the burner tothe special arrangement of holes or ignition-apertures 29, hereinbeforedescribed; nor do I confine in every instance the special arrangement ofignitionapertures to the special forms of burner shown.

What I claim as my invention, and desire to secure by Letters Patent, is

1. An elongated gas-burner having the outer convex wall and the innerconcave wall. said walls forming between them the elongated chamber ofconcavo-convex form in crosssection and decreasing in depth, radiallyconsidered, from its center to its side edges, and said outer wall beingprovided with ignitionapertures; substantially as set forth.

2. An elongated burner having the outer and inner walls and formingbetween them the chamber of concavo-convex form in cross-section and ofuniform cross-sectional area, said outer wall being provided with theseries of straight transverse rows of small round igbeing close togetherso that their flames may commingle and said rows being about two inchesapart to prevent the flames at one row from commingling with the flamesat the adjacent rows; substantially as set forth.

Signed at New York, in the county of N ew York and State of New York,this 30th day of December, A. D. 1903.

DAVID B. FRASER.

Witnesses:

CHAS. (J. GILL, ARTHUR MARION.

